inspection blood blisters of a reddish-brown or purple colour may be seen
on the meatal walls (otitis externa haemorrhagica), close to the annulus and
on the tympanic membrane (Plate X, 5) (myringitis bullosa). The bullae are
prone to spontaneous rupture, with bloodstained discharge from the ear which
may be profuse. The infecting organism is a haemolytic streptococcus com-
bined with a virus. These blisters may occur independently of any middle ear
lesion, and in such cases the hearing is practically normal. In the majority
of cases, however, the bullae are associated with an otitis media, for the
subperiosteal space of the posterior meatal wall is in anatomical continuation
with the submucous space of the tympanum.
TREATMENT. Incision of the bullae is not indicated unless otitis media with
exudate in the middle ear is present, when there will be conductive deafness
and severe pain. A course of antibiotics, either penicillin or ampicillin, should
be given and sedatives may be required for the pain. The meatus may be
lightly plugged with cotton-wool.
Malignant Otitis Externa
The majority of reported cases of this uncommon disease have occurred in
elderly diabetics. It is characterized by increasingly severe pain in the ear
and purulent discharge. The organism responsible is Ps. pyocyaneus. Granu-
lation tissue is present in the floor of the meatus at the junction of the carti-
laginous and osseous portions. Infection spreads to the deeper tissues through
the normal clefts in the cartilage of the floor to involve the parotid gland and
structures at the base of the skull. Despite energetic management of the
local infection the disease is often progressive causing widespread osteo-
myelitis, intracranial complications and death.
TREATMENT. Granulation tissue should be removed and necrotic tissue
excised from the meatus to which daily packs of ribbon-gauze wicks impreg-
nated with gentamicin ointment (Cidomycin, Genticin) are applied. The
administration of gentamicin intramuscularly and carbenicillin intravenously
in full dosage is also recommended. Progress of the infection may necessitate
a wide excision of tissues.